Most modem telephones include a speed dial feature. A typical speed dial feature is embodied in one or more speed dial buttons forming part of a telephone keypad. The purpose of the speed dial buttons is to make it easier for the owner of the phone to place outgoing calls to frequently called telephone numbers, such as to the numbers corresponding to friends and family. Typically, a telephone will have a plurality of speed dial buttons, each associated with a specific party to which the telephone owner may frequently place outgoing calls. Instead of pressing the sequence of buttons corresponding to an intended party's telephone number, the telephone owner simply activates the appropriate speed dial button. A processor within the telephone then associates the activated speed dial button with the desired telephone number, and creates a sequence of signals, such as dual tone multi-frequency (DTMF) signals, to mimic the sequence that would have been produced by the phone if the caller had pressed the sequence of buttons.
Instead of a series of speed dial buttons, an alternative speed dial feature includes a single speed dial or memory button that is activated in association with conventional numeric keys on a telephone keypad. According to this embodiment, for example, a user presses "memory" "1", by first pressing the "memory" key and then pressing the "1" key, in order to call the first speed dial number. Similarly, "memory" "2" causes the second speed dial number to be called. In each case, the telephone includes a memory, such as a random access memory, having a plurality of storage locations. Each memory location holds a unique telephone number that is associated with a speed dial button or sequence. When the speed dial feature is activated, a processor retrieves the number from the corresponding memory location and initiates a DTMF dialing sequence.
The speed dial feature is advantageous to many users because it allows them to place many outgoing calls by pressing a single button, instead of pressing a series of buttons. This advantage is becoming more significant as the telephone number density continues to grow to the point where even local telephone calls frequently require ten-number "dialing". In this context, of course, "dialing" typically refers to the activation of a button on a keypad, and not the rotary displacement of a dialing mechanism. Further, the speed dial feature relieves the telephone owner of the burden of remembering telephone numbers associated with the parties whose numbers are associated with the speed dial buttons.
Over time, however, a typical speed dial user may no longer remember a telephone number of a friend or family member. For example, a speed dial user may simply remember that to place a call to her mother she presses the first speed dial button, and to place a call to her brother she presses the second speed dial button, and have no recollection of the actual telephone number called when these speed dial buttons are pressed. Thus, if a speed dial button no longer functions, the user may be unable to immediately call the party associated with the speed dial button. For example, a speed dial button may become non-functioning if there is a change in the phone number of the party associated with the speed dial button. Such a change in phone number may occur, for example, when the party moves or when there is a change in the area code of the party associated with the speed dial button. There is a need, therefore, for a mechanism to automatically update speed dial buttons when a telephone number changes, such as when a party moves or when a party's area code changes.